Snap-acting fluid metering valve device



J. T. ABDO Filed Sept. 30. 1950 SNAP-ACTINGFLUID METERING VALVE DEVICE INVENTOR: JOSEPH T. A BDO ATTUHNEX Nqv. 30, 1954 United States Patent O SNAP-ACTING FLUID NEETERING VALVE DEVICE Joseph T. Abrlo, Minneapolis, Minn., assignor to Minneapolis-Honeywell Regulator "Company, Minneapolis, Minn., a corporation of Delaware Application 'September 30, 1950, Serial No. 187,751

12 Claims. (Cl.I2`51'-13) This invention relates to uid metering means and,

more particularly, to Ametering `means 'for delivering oil.

to an oil burner ata uniform rate.

Prior art arrangements for delivering `oil tto a burner have generally taken .the form of a constant level coil valve wherein the uidtoroil is `maintained ata predetermined elevation above the `oil foutlet in the lburner with the rate of uid iiow :from said rconstant level valve `controlled by va needle valve. Unless this type `of bvalve is also provided with complicated `and teostly means to compensate for variations in 'the 'oil temperature, Ythe changing viscosity of the oil materially aieets the :rate of oil iiow and, consequently, the ;heaft output 4foi the burner.

Another `type of,v oil metering means in ,general use has been a `device wherein `a pressure regulator, receiving oil `:from a positive 'displacement pump, maintains `the pressure of the'oil lat the burner'at `substantiallyza uniform pressure. Here again, with changes iin temperature and viscosity, the quantity of the `fuel delivered .and the heat produced `b y the burner varies. This l.arrangement also requires additional compensating means to .assure uniform `delivery of o'il regardless of temperature change.

It is an objectof this invention Yto provid'ea simple, :inexpensive, reliable, and compactfuelfmetering means that requires no complicated or expensive-compensatingmeans to :assure substantially uniform 'fuel ow.

'Another object of the invention 'is to provide a Afuel metering means which makes Yus'eol the head of oil in the supply source `to cause .actuation -of the 'fmetering means.

Another `object of ythe ainvention 'is `to :provide a metering device of .the accu'i'nulator .type wherein a timing means for the discharging of :fuelfrom said accumulator is hydraulically controlled.

.A'further object of the 'invention .is .to provide a metering device of the Vaccumulator type wherein 1a movable Wall of the laccumulator actuates 4a vsnap valve that `controls the inlet and loutlet Lports to the accumulator.

Another object fof the invention is to fprovide a snap acting valve which -is loaded fin `one direction only and which ris `actuated in 'its other 'direction by means fof `inlet ud pressure acting on al1-.actuator fior said valve.

Still another object -of the `invention .is to .fprovide a snap acting valve which 4is biased fin `one direction iconstantly by `a resilient -means 'and 'is alternately "biased in opposite `directions :by `snap means .having a Sbiiurcated resiilient reed acting on spaced actuator 2arms for the va ve.

l.Another object of lthe .invention ,lis '-to .provide .a fuel metering 4device which fis fhydraulically controlled by .a iiuid `the viseosityfof which does-not varyover wide temperature ranges.

Additional objects of the invention =.will `become apparent lupon readingltheiollowing detailed .description of the invention infconjunction `with the .drawing wherein:

VFigure l lis `a @side elevational 'view of tthe :metering device, partly in cross sectionandwth `afportion fthereof broken away;

Figure 2 is a perspective'vi'ew of :the snap acting icontrol valve with its cover removedg-and -Figure 3is-a sectional view .taken alongthe :line 3-3 of-Figure 2, showing the actuating .lever .for the `control valve in another .of its operatingpositions.

"The.preferredembodimentiof thevrneteringdevicecomprises `four =main .body ,portions 10, I:1-1, 1-2 and .13 which are lclamped ,together by .means of bolts 14, with .the portions 11, 12 and I.13 additionally vheld together .by

' described hereinafter.

2,695,765 Patented Nov. 30, 1954 ice bolts 15 and the portions 10 and 11 :additionally held by bolts .16 and screw 1'1. A diaphragm 18 is clamped circumferentially vbetween opposed surfaces of the portions 11 and 12 while gaskets (not shown) are provided between the portions 12 and `13 and the portions 10 and 11 'to provide .fluid tight joints therebetween. A cover 10a is zsecured to the body portion 10, with a gasket (not shown) therebetween, by means of screws 19 extending through holes in the cover 10a in .alignment with threaded bores 19a. Two bolts .-14 extend completely'throughholes in @body portions 11, l12 and 13 land are screw threaded into threaded bores 14a in body portion 10. Bolts 16 extend through holes in a wall of `body portion 11 and are screw threaded in threaded bores 16a in body portion 10. Screw 17 extends through a .iiange 10b on the cover 10a and is screw threaded into body portion 11.

-Body portion 10 (best fseen in Figure 2 of the drawing.) has a threaded inlet port 20 adapted to be connected by a pipe 21 to a sourceof fuel (not shown) at an elevation above Ithat of .the @meter-ing device. A .fuel supply control valve 522 may be of the manually foperable type or may be V.of the `conventional .safety type which 4is thermostatically controlled. A threaded .outlet .port 23 is lin ,axial alignment with the inlet port 20 and is adapted -to be connected to a .burner (not shown) through ra `conduit 24.

.A valve stem .25 carries an inlet valve head .26 at :one end -thereofand an outlet valve .head .27 .at the other .end thereof. .Brongs 26a extending longitudinally outwardly from the heads 26 and 27, respectively, engage the inner Unthreaded-ends -of the inlet and outlet passages 20 and 23 rrespectively, -or -holding said valve in .centered `position over the :inner ends of said inlet and outlet, to assure ,proper seatingthereof. It -will be noted that `when the valve head -27 is in seating relationship with rheinner .end of )the outlet r.passage 23, the valve head 26 is raised .out of .seating lengagement .with the inner end -of inlet 2901=so as .to lpermit .ow of ...fluid `through said .inlet and between the [prongs `26a into a chamber 28 within the bodyportion 10. Atransversely extending arm 29 is secured to the 'stem 25 intermediate `its end .to serve as an .actuating `means for `the valves 26 and 27.

A lever or crank 30, secured `to fa wall of the body portion 10 by meanscof ar-,pivot 31 `near one-of its ends, has a slightly elongated aperture 32 therein near .its free end, .throughfwhich .thepin 29 extends for actuation thereby. .A :coiled tension .spring normally biases .the crank =in 1.a direction `to cause the valve 27 to close. Transversely-extending arms.34 and-35am formedon the pivoted end of the Acrank 30, one on Veach side of the pivot `31.

Cooperating with the arms 34 and 35 is ,a .quite `stili resilient reed 36 having a bifurcated free end providing tines 36a and 36h cooperable .witth the arms 34 and 35, respectively. The other end of the reed is clamped in.a slot l.37 "formed `in ralblock 38 atan acute `angle with respect to a =stem 39 extending 4vertically .through .said block .38, .as viewed iin the drawing. The reed .36 is clamped `in said lslot.37 -by means of `screws V4Ilextending throughalignedholes (nottshown) in the block andzthe reed `36 and screw threaded into that portion of the block 381m ithe yopposite -side 4.of .the reed from rthe :screw heads. The stem 39 isgguided for verticalmovement by the lupper'end thereof extending tinto a bore 41 in one wall of the body portion .andrinto .a bore 42 in .a boss 43 on antopposite wall of.said body portion 10. To prevent .rotationnof thelstem 39K, alpin'f44'is suitably Asecured to .the Vstem .39 -for vertical .movement only in a slot45 in the-boss S43. fItiis .thus seen `that the reed 36 can travel only ina vertical direction, except for whatever .horizontalmovernent 'that may be impartedto the free endithereofdue to engagement of said free end with a .iixedlaabutment fas 4the :reed moves vertically, as will obviously take .place lwhen .the .reed 36 moves verticall; with-respect to the arms..34and A35, :which action will be :Two :spaced pins 46 fare secured to `and-extend laterally from the. stem 39 tor .engagement by an .actuatingmeans Ito .be ,presently described.

iBody portion .11, l.which .joins the tbody .portion 10, has Ya two-'way .iluid passage 47 providing communication `between the chamber .28 .of .body .portion `10 .and

an accumulator chamber 48 formed between a side wall of the portion 11 and the diaphragm 18. A second opening 49 between the chambers 28 and 48 has a bell crank lever 56 pivoted therein. One of the arms of the bell crank lever extends between the pins 46 on the stem 49 for actuation thereof while the other arm of the bell crank lever has a bifurcated free end 51 which straddles a pin 52 on a bolt 53. The bolt 53 extends through a hole (not shown) in the center of the diaphragm 18 and clamps the center portion of said diaphragm in sealing relationship to the bolt 53 by means of washers 54. The end of the bolt 53 in the chamber 48 has an apertured lug 55 thereon which is engaged by one end of a coil spring 56 which has a low spring constant to reduce its effect on ow rate per cycle. The other end of the coil spring 56 is swivelly connected to an adjusting screw 57 extending through a packing nut 58 and screw threaded into a recessed side wallv 11a of the body portion 11. By arranging the elements of the device so that the diaphragm will be horizontally disposed, a weight may be substituted for the spring 56, thus providing a constant biasing force over the entire expelling stroke of the diaphragm.

The upper portion of the body portion 12 (as viewed in the drawing) has a transversely extending bore 59 which is vented to the atmosphere through an opening 60 in the top of said bore and which communicates with a chamber 61, formed between a side wall of the body portion 12 and the diaphragm 18, by means of a passage 62. The chamber 61 is lled with glycerin or similar uid. A ball check valve 63 permits fluid flow from chamber 61 into the bore 59 but prevents reverse flow from said bore to said chamber. A pin 64 secured to a wall of the bore 59 prevents the ball 63 from moving laterally out of position with respect to passage 62. The lower portion of the side wall of the body portion 12 has two ports 65 and 66 therein through which fluid may pass between chamber 61 and chamber 67 formed between the side wall of the body portion 13 and the side wall of body portion 12. The chamber 67 also has communication with the bore 59 through a passage 68 formed in the upper part of portion 13 and is likewise lled with the same fluid as is in chamber 61.

The body portion 13 has two bosses 69 and 70 in axial Valignment with the ports 65 and 66, respectively. Threaded needle valves 71 and 72 extend through packing nuts 73 and 74, respectively, on said bosses and are adjustably threaded through bores in said bosses so as to regulate the rate of fluid ow through the ports 65 and 66 respectively. It is intended that one of the needle valves be used to provide a constant minimum How of fuel' to the burner, while the other of said needle valves is intended to be operated between a closed position and a predetermined open position, either manually or automatically, to vary the rate of ow between the chambers 67 and 61, when it is so desired.

Operation Assuming that the metering device as shown in the drawing is connected to a source of fuel supply, such as an oil storage tank, and the conduit 24 is connected to a burner in a furnace, the elements of the device are illustrated in Figures l and 2 as seen in the positions they would assume near the end of the accumulator charging movement of the diaphragm 18. That is, the inlet valve 26 is open, the outlet valve 27 is closed, and the pressure of the oil in the supply tank is forcing the diaphragm toward the right against the bias of spring 56 to accumulate oil in the chamber 48. In this movement of the diaphragm 18, the bell crank lever t) is being rotated in a counterclockwise direction which causes the stem 39 and the reed 36 thereon to move downwardly. As the crank arms 34 and 35 are engaged on their same sides by tines 36a and 36b, respectively, the downward movement of the stem 39 and reed 36 will not cause any rotation of the crank but the arm 34 will deect or bend the reed 36 transversely until the upper edge of tine 36a has passed below the lower edge of the arm 34. When the tine 36:1 has cleared arm 34, the'then bent reed 36 will snap or whip the arm 35 through tine 36b in a counterclockwise direction about pivot 31, the width of the tine 36b being such that it still is in engagement with the arm 35. This causes the crank 30 to actuate the valve 26 to its closed position and valve 27 to its open position, through the rod 29 and stem 25 against the bias of spring 33.

With the valves 26 and 27 in their new position, the oil in chamber 48 is then free to be expelled to the burner by means of the diaphragm 18 being biased toward the left by the spring 56. The rate at which the diaphragm 18 moves toward the left is controlled by the size of the opening of ports 65 and 66, the glycerin in chamber 67 or the air above the glycerin in said chamber being unable to flow into chamber 61 through the passage 62 due to the fact that the ball check valve 63 is closing said port 62. Thus, with the valve 72 in an open position, the position that it would have when it is desired to operate the burner to provide heat, the diaphragm 18 will deliver oil to the burner at a higher rate than if the valve 72 were closed and glycerin in chamber 67 were permitted to ow into chamber 61 only through the nearly closed port 65, as when only sufficient oil is desired to maintain a pilot flame. It might be observed at this time that all of the passages supplying oil are of substantial cross-sectional area which makes the oil flow less critical to changes in the viscosity of the oil than if there were restrictions in said passages. The metering of the oil delivery is thus controlled by the flow of a uid, glycerin, or some other suitable fluid, .which does not change the viscosity over a wide temperature range so that, practically, its rate of How through the restricted ports 65 and 66 does not vary with temperature but solely by the position of the needle valves 71 and 72.

As the stern 39 starts to move upwardly under the bias of spring 56 acting through crank 50, the reed 36 will assume the position shown in Figure 3 of the drawing. The reed 36 which is then engaging the arm 35 on the left hand side thereof (as viewed in the Figure 3 of the drawing) will move up into engagement with the right hand side of the arm 34. Further upward movement of the reed 36 will tend to cause the reed 36 to leave the pin 35 but exert an increased pressure on the arm 34, which will continue to hold the crank 30 and the valve 26 down against the bias of spring 33. However, as the pin 34 cannot move counterclockwise due to the fact that it has reached its lower limit of travel, the reed 36 will be bent toward the right in gradually increasing amount until the lower edge of the tine 36a has cleared the upper edge of the arm 34. When this happens, the bent reed 36 will snap toward the left, as viewed in Figure 3, followed by the arm 35 as the arm 34 passes through the space between the tines 36a and 36b, under the bias of spring 33. It will be observed that when the spring 33 rotates the crank 30 about pivot 31 so as to .move the arm 34 through said space, the valve 26 will be raised to its open position and the valve 27 to its closed position. lt is thus seen that at each end of the travel of the diaphragm 18, the snap acting mecha,

nism operates control valves 26 and 27 with a snap action alternately to their open and closed positions.

The elements of the metering device have now reached the position they assume at the start of a charging stroke. As the diaphragm 18 starts to move toward the right, tines 36a and 36h will move into engagement with the left hand side of the arm 34 as shown in Figure 2 of the drawing. Continued upward movement of the reed 36 under the action of diaphragm 18 will cause a repetition of the above described operation of the metering device.

It is deemed obvious that any suitable automatic and well known control means could be used to operate the valve 72 in response to room temperature to automatically place the metering device into operation.

As it is also obvious that various modifications may be made in the structure o f the illustrated preferred embodiment of the invention, and that various substitution of equivalents may be made therein without departing from the spirit of the invention, it is to be expressly understood that the scope of the invention is to be determined solely by the appended claims.

I claim as my invention:

1. A fluid metering device comprising a housing having an inlet and an outlet, rst and second chambers separated by a movable wall, said inlet and outlet being in communication `with said first chamber, a third chamber having a plurality of passages extending therefrom to said second chamber, a liquid lling said second chamber and substantially lling said third chamber, a

aeesgves check valve .for permitting liquid ilowthrough one-of said passages from said second chamber `to said third chamber but preventing reverse flow therethrough, at least one adjustable valve `for regulating `the rate :otfliquid flow through another :of said passages, a Acontrol valve for alternately permitting liquid flow from said inlet to said first chamber and from said first chamber to said outlet, snap acting means operably connecting said control `valve tovsaid `movable Wall, and means biasing said wall `in a direction to `'ex-xpel liquid from said first chamber and to move said control valve .to the position permitting liquid flow to said first -chamberfrorn isaid inlet.

`2. A fluid `metering device `comprising a housing having an yinlet rand `an outlet, first and :second chambers separated by a movable wall rand a .third chamber -having a plurality of `passages `extending therefrom to said `second jcharnber, 1a first valve seat rbetween said inlet and said first chamber and a `second valveiseat between said first chamber and said outlet, a check valve for permitting fluid flow through one of said passages from said second chamber to said third chamber but preventing reverse flow therethrough, at least one adjustable valve for regulating the rate of fluid flow through another of said passages, a control valve for alternately engaging said first and second valve seats and means biasing said valve toward the second valve seat, means connecting said control valve to said movable wall, and means biasing said wall in a direction to expel fluid from said first chamber and to move said control valve against said second valve seat.

3. A fluid metering device comprising a housing havving an inlet and an outlet, first and second chambers separated by a movable wall and a third chamber having a pluraltiy of openings extending therefrom to said second chamber, passages extending from said inlet and outlet to said first chamber, a check valve for permitting lluid flow through one of said openings from said second chamber to said third chamber but preventing reverse flow therethrough, at least one adjustable valve for regulating the rate of fluid flow through another of said openings, a control valve for alternately connecting said first chamber to said inlet and said outlet through said passages, means connecting said control valve to said movable wall, and means biasing said wall in a direction to expel fluid from said first chamber and to move said control valve to a position connecting said first chamber to said inlet.

4. In a fluid metering device, the combination comprising a housing having first, second and third chambers, a movable wall between the first and second chambers and an apertured fixed wall between the second and third chambers, said first chamber having an opening therein, a control valve having an inlet and an outlet with a fourth chamber therebetween connected to said opening, said control valve having valve operating means connected to said movable wall, and resilient means normally biasing said valve operating means in a direction to move said movable walls to increase the size of the second chamber and to move said control valve in a direction to establish communication between said inlet and said fourth chamber while simultaneously closing said outlet, said movable wall being movable under inlet fluid pressure to a position clcsing said inlet and opening said outlet by said control va ve.

5. In a fluid metering device, the combination comprising a housing having first, second and third chambers, a movable wall between the first and second chambers and an apertured fixed wall between the second and third chambers, said first chamber having an opening therein, a control valve having an inlet and an outlet with a fourth chamber therebetween connected to said opening, said control valve having valve operating means connected to said movable wall, biasing means normally biasing said valve operating means in a direction to move said movable wall to increase the size of the second chamber and to move said control valve in a direction to establish communication between said inlet and said fourth chamber while simultaneously closing said outlet, said movable wall being movable under inlet fluid pressure to a position closing said inlet and opening said outlet by said control valve, and snap-acting means controlling the movement of said control valve and operated by said movable wall.

6. In a fluid metering device, the combination com- 6 prising a housing having first, second and `third nham bers, a movable wall between the first and :second chambers and an apertured fixed wall between 1lthe :second and .third chambers, said first chamber `having ian opening therein, `a control valve having 'an (inlet and an outlet -with a fourth chamber `therebetween connected to said opening, ksaid control valve .having valve :operated means `connected to saidmovable wall, vmeans vby which said valve operating means is normally 'biased in a direetion to `move said movable `walls `to increase the size ofthe second chamber and to `move said control valve in a direction to establish communication between said inlet and said fourth chamber while simultaneously closing said outlet, said movable wall being movable under inlet fluid pressure 'to a position closing said inlet and opening said outlet `by said control valve, `and snap-tact'- ing `means controllingthe 'movement of :saidcontrol valve.

"7. A device for metering `fluid `comprising an accumulator having a movable Wall, a control valve, snap acting means operable by said movable wall for actuating said control valve, an inlet and an outlet for said accumulator alternately opened and closed by said control valve, means biasing said movable wall in a direction to expel fluid from saidJ accumulator when said outlet is open and said inlet is closed but operable under inlet pressure against said bias to permit said accumulator to fill when the outlet is closed and the inlet is opened, and means controlling the rate of movement of said movable wall in its expelling operation.

8. A device for metering fluid comprising an accumulator having a movable wall, a control valve, snapacting means operable by said movable wall and operably connected to said control valve, an inlet and. an outlet for said accumulator alternately opened and closed by said control valve, means biasing said movable wall in a direction to expell fluid from said accumulator when said outlet is open and said inlet is closed but operable under inlet pressure against said bias to permit said accumulator to fill when the outlet is closed and the inlet is opened, and means controlling the rate of movement of said movable wall in its expelling operation.

9. A device for metering fluid comprising an accumulator having a movable wall, a control valve operable by said movable wall, an inlet and an outlet for said accumulator alternately opened and closed by said control valve, means biasing said control valve in a direction to open said inlet, means biasing said movable wall in a direction to expel fluid from said accumulator when said outlet is open and said inlet is closed but operable under inlet pressure against said bias to permit said accumulator to fill when the outlet is closed and the inlet is opened.

l0. In a fluid metering device, an accumulator having a movable wall, a double-headed valve member controlling the flow of fluid to and from said accumulator and operable by said movable wall, and snap-action means between said movable wall and said valve member comprising a crank having an actuating arm engaging said valve member and mounted on a pivot spaced from said valve member, a pair of parallel crank arms on said crank on opposite sides of said pivot, a non-rotatable rectilinearly slidable stem in a plane parallel to said crank, means operably connecting said movable wall to said stem, and a fiat reed having a bifurcated end cooperable with said pair of crank arms for actuating said valve member, said reed being at substantially a right angle to said stem and connected at its other end to said stem with the plane of said reed at an acute angle to the 'axis of said stem.

ll. In a fluid metering device, an accumulator having a movable wall biased in a direction to expel fluid from said accumulator, a double-headed valve member controlling the flow of fluid to and from said accumulator and operable by said movable wall, and snap-action means between said movable wall and said valve member comprising a crank having an actuating arm engaging said valve member and mounted on a pivot spaced from said valve member, a pair of parallel crank arms on said crank on opposite sides of said pivot, a non-rotatable rectilinearly slidable stem in a plane parallel to said crank, means operably connecting said movable wall to said stem, and a at reed having a bifurcated end cooperable with said pair of crank arms for actuating said valve member, said reed being at substantially a right angle to said stem and connected at its other end t to said stern with the plane of said reed at an acute angle to the axis of vsaid stem.

12.` In a uid metering device, an accumulator having a movable wall, a double-headed valve member controlling the flow of fluid to and from said accumulator and operable by said movable wall, and snap-action means between said movable Wall and said valve comprising means biasing said valve member in a direction to permit fluid ow into said accumulator, a crank having an actuating arm engaging said valve member and mounted on a pivot spaced from said valve member, a pair of parallel crank arms on said crank on opposite sides of said pivot, a non-rotatable rectilinearly slidable stem in a plane parallel to said crank, means operably connecting said movable wall to said stem, and a flat reed having a bifurcated end cooperable with said pair of crank arms for actuating said valve member, said reed being at substantially a right angle to and connected at its other end to said stem with the plane of said reed at an actute angle to the axis of said stem.

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